To realize the potential of nanomedicine to revolutionize health and medicine, intracellular molecular mechanisms will have to be elucidated. The accelerating progress in cataloguing the critical molecular and structural elements responsible for cell function has led to the hope that cell biological processes can be analyzed and understood in terms of the interactions of these components. Currently, efforts to characterize and analyze cellular mechanisms focus on interactions between molecules that comprise biochemical and gene-regulatory networks. The study of such networks is a central theme of the emerging field known as Systems Biology. However, this focus alone can never provide answers to the key question on the origin and role of spatial organization at supramolecular scales within the context of a cell. This nanoscale bridges molecular level detail, which is derived from biochemistry and molecular structure, and the micro level detail that is derived from studies of cell function and dynamics. The proposed "Center for Cellular Nano-Organization" (CNO) will focus on intracellular dynamic structures at this intermediate scale and explore how these structures are generated and how they mediate key cellular events. This will be achieved through a series of specific collaborative interdisciplinary projects that will explore the assembly and function of prototypical cellular structures, which we call intracellular nanomachines, in carefully selected appropriate cell biological systems. These projects will call upon the expertise and tools available in 3 technology cores: Optics Lab, Modeling Lab and Computation Lab. The latter will also offer web-based services that will assure that the products of the CNO will be available to the other Nanomedicine Centers and disseminated to the greater biomedical research community. We anticipate that these studies will lead to new unifying principles on the initiation, self assembly and function of spatially organized intracellular nanostructures.